1. Field of the Invention
The invention relates to display manners of portable electronic devices and more particularly to methods for adjusting display manners of portable electronic devices.
2. Description of the Related Art
Current portable electronic devices such as smart phones and tablets often automatically determine rotating directions of screens according to sensing values of gravity sensors (G-sensor) or orientation sensors. A gravity sensor may detect a change in the gravitational direction of a portable electronic device, and thus a display direction of a screen of the portable electronic device may be adjusted accordingly so as to be suitable for users when they watch the screen or manipulate the portable electronic device. For example, when the portable electronic device is oriented in a portrait orientation (that is, the right side and the left side of the portable electronic device are long sides and the top side and the bottom side of the portable electronic device are short sides), the screen is under a portrait mode, and when the portable electronic device is oriented in a landscape orientation (that is, the right side and the left side of the portable electronic device are short sides and the top side and the bottom side of the portable electronic device are long sides), the screen is under a landscape mode. However, if an angle between the portable electronic device and the horizontal plane (ground plane) is not sufficiently large enough, for example, when the portable electronic device is laid on a table, even though a user rotates the portable electronic device (that is, the screen is almost parallel to the horizontal plane while the user rotates the portable electronic device), three dimensional components of the gravitational direction affecting to the portable electronic device barely change. Thus, the gravity sensor may not effectively determine the proper rotated direction of the screen. In this case, a user usually needs to do extra actions, such as erecting the portable electronic device first, rotating the portable electronic device to the desired direction and then laying the portable electronic device on the table, to make the screen display in the desired display mode. Accordingly, a user may feel that this is inconvenient.